The present disclosure relates, in various embodiments, to methods for making a semiconductor layer for electronic devices, such as organic thin-film transistors (“OTFT”s), with increased charge carrier mobility through acid doping of the semiconductor layer. The present disclosure also relates to semiconductor layers produced using the methods and electronic devices containing such semiconductor layers having enhanced charge carrier mobility.
Thin film transistors (TFTs) are fundamental components in modern-age electronics, including, for example, sensors, image scanners, and electronic display devices. TFT circuits using current mainstream silicon technology may be too costly for some applications, particularly for large-area electronic devices such as backplane switching circuits for displays (e.g., active matrix liquid crystal monitors or televisions) where high switching speeds are not essential. The high costs of silicon-based TFT circuits are primarily due to the use of capital-intensive silicon manufacturing facilities as well as complex high-temperature, high-vacuum photolithographic fabrication processes under strictly controlled environments. OTFTs offer not only much lower manufacturing costs, but also appealing mechanical properties such as being physically compact, lightweight, and flexible.
OTFTs are generally composed of a supporting substrate, three electrically conductive electrodes (gate, source and drain electrodes), a channel semiconductor layer, and an electrically insulating gate dielectric layer separating the gate electrode from the source and drain electrodes. The channel semiconductor is in turn in contact with the source and drain electrodes. The materials used to make the OTFTs, and the interfacial properties between various layers of semiconductor, dielectric, and electrodes will affect the performance of the OTFTs. Accordingly, a great deal of recent effort has been devoted to improving the OTFT device performance through new semiconductor materials design, improvement of semiconductor ordering, and optimization of semiconductor and dielectric interface, etc. There is a further need for methods which will increase charge carrier mobility in the semiconductor layer.